Fire, acoustic, and thermal resistant construction

ABSTRACT

A structure having an area separation wall including: a first building unit; a second building unit; and an area separation wall having only outer membranes. Preferably, the area separation wall is fire resistance rated. The outer membranes provide acoustic attenuation without adversely affecting the fire resistance of the area separation wall. The area separation wall provides improved thermal resistance. In one embodiment, the area separation wall includes: an interior support structure and at least one outer membrane on each side of the interior support structure. The outer membranes provide acoustic attenuation. Between the outer membranes is a substantially organic material barrier. The structure may also include a tying structure connecting the area separation wall to the first unit and the second unit.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates generally to a structure having a fireresistance rated, area separation wall and, more particularly, to a fireresistance rated, area separation wall for a structure which alsoprovides acoustic attenuation and thermal resistance without adverselyaffecting the fire resistance of the area separation wall.

(2) Description of the Prior Art

Multi-family residential constructions typically include a separationwall constructed of wood members and having a material barrier betweenthe units. These wood members may include dual two-by-four framing witha drywall surface on both sides of the framing. In most cases, this typeof construction requires that the drywall be attached to the interiorsurface of the framing before the framing is placed upright to serve asa wall. After the framing is placed upright, insulation material may bepositioned in the framing, and later an additional drywall membrane isfastened to the outside of the framing to complete an interior wall.This process is expensive, labor-intensive and time consuming.

One purpose of such a dual membrane construction of an area separationwall is to provide a fire resistance separation between adjacent spacesto meet federal, state and local regulations concerning the fireresistance of such a construction. Underwriters Laboratories Inc. (UL),an independent, not-for-profit product safety testing and certificationorganization, has been testing products for public safety for more thana century. Because UL has an undisputed reputation as the leader in U.S.product safety and certification, it is advantageous to obtainclassification of a building product by UL. One UL test, ANSI/UL 263(ASTM E119 and NFPA 251), involves rating such a separation wall forfire resistance. If a separation wall including only outer membranescould be developed that is sufficiently fire resistant to gain ULclassification for more than two hours, such a separation wall would beless costly to construct than a conventional separation wall.Additionally, there is a need for providing walls that provide acousticattenuation, especially as more and more condominiums and townhouseshaving shared walls are built.

Another purpose of such a dual membrane construction of an areaseparation wall is to provide improved acoustic and thermal resistance.

Thus, there is a need for a structure having an area separation wall,the structure including a first and second building units and an areaseparation wall having at least one outer membrane. There is also a needfor an area separation wall that provides acoustic attenuation andimproved thermal resistance without adversely affecting the fireresistance of the area separation wall.

SUMMARY OF THE INVENTION

The present invention is directed to a structure having an areaseparation wall including: a first building unit; a second buildingunit; and an area separation wall having only outer membranes. The areaseparation wall provides improved fire, thermal, and sound resistance.The outer membranes provide acoustic attenuation without adverselyaffecting the fire resistance of the area separation wall.

In an embodiment, the area separation wall includes: an interior supportstructure; at least one outer membrane on each side of the interiorsupport structure, the outer membranes providing acoustic attenuation;and a substantially organic thermal material barrier between the outermembranes. The structure may further include a tying structureconnecting the area separation wall to the first unit and the secondunit.

In an embodiment, the tying structure may include a top plate attachedto the top edge of said area separation wall and a bottom plate attachedto the bottom edge of said area separation wall. The tying structure andsaid top plate may form a double top plate. The top plate and saidbottom plate may be less than about 10 feet apart.

In an embodiment, the first building unit is an occupiable space and theoccupiable space is residential. The residential occupiable space may bea town home. The second building unit may be an occupiable space. In anembodiment, the occupiable space is residential. The residentialoccupiable space is a town home.

The interior support structure may include at least two structuralinterior support members. The structural interior support members mayinclude a plurality of vertical members. The plurality of verticalmembers may be spaced apart. The plurality of vertical members arespaced apart no more than about 24 inches. Preferably, the plurality ofvertical members are 2×4 wood. The plurality of vertical members may be2×4 metal.

The plurality of vertical members may be 2×10 or less thicknessdimension of a material selected from the group consisting of wood,metal, other materials, and combinations thereof. The plurality ofvertical members further include cross bracing at about the mid heightof said plurality of vertical members. There may be a physical gapbetween said structural interior support members.

In a preferred embodiment, the outer membranes are fire resistantwallboard. Preferably, the fire resistant wallboard is a gypsumwallboard (GWB) Type X or Type C as defined in ASTM C11. The gypsumwallboard conforms to ASTM Test C-36-96. Preferably, the substantiallyorganic material barrier is selected from the group consisting offibrous material, granular material, pellet material, aggregatedmaterial, agglomerated material, closed cell foam, open cell foam, fireretardants, binders and mixtures thereof. The substantially organicmaterial barrier may be a natural material. The natural material iscellulosic. In an embodiment, the substantially organic material barrierincludes an inorganic material. The inorganic material is selected fromthe group consisting of fiberglass, rock wool, pearlite, mineral wool,asbestos, cementitious materials, fire retardants, binders, and mixturesthereof. Preferably, the substantially organic material barrier is anacoustically transmission resistive material.

In an embodiment, there are an unequal number of like outer membranes.The outer membranes may be of unequal thickness. The outer membranes maybe made of unlike materials. In an embodiment, the outer membranes maybe made of unlike materials and are of unequal thickness.

Accordingly, one aspect of the present invention is to provide astructure having an area separation wall. The structure may include: afirst building unit; a second building unit; and an area separation wallhaving only outer membranes, the outer membranes also providing acousticattenuation. The area separation wall provides improved fire, thermaland sound resistance and combinations thereof.

Another aspect of the present invention is to provide an area separationwall for a structure. The area separation wall may include: an interiorsupport structure; and at least one outer membrane on each side of theinterior support structure. The outer membranes provide acousticattenuation; and a substantially organic material barrier between theouter membranes. The area separation wall also provides improved fire,thermal and sound resistance and combinations thereof.

Still another aspect of the present invention is to provide a structurehaving an area separation wall. The structure may include: a firstbuilding unit; a second building unit; and an area separation wall. Thearea separation wall may include: (i) an interior support structure;(ii) at least one outer membrane on each side of the interior supportstructure, and (iii) a substantially organic material barrier betweenthe outer membranes; and a tying structure connecting the fireresistance rated, area separation wall to the first unit and the secondunit. The outer membranes may provide acoustic attenuation. The areaseparation wall also provides improved fire, thermal and soundresistance and combinations thereof.

These and other aspects of the present invention will become apparent tothose skilled in the art after a reading of the following description ofthe preferred embodiment when considered with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a structure having an areaseparation wall constructed according to the present invention;

FIG. 2 is a side view of the area separation wall for a structure shownin FIG. 1 including a tying structure;

FIG. 3 is a side view of the area separation wall for a structure shownin FIG. 1 without a tying structure;

FIG. 4 is a side view of an embodiment of the area separation wall for astructure shown in FIG. 1 without a tying structure and with anadditional outer membrane on a side of the area separation wall;

FIG. 5 is a side view of an embodiment of the area separation wall for astructure shown in FIG. 1 without a tying structure and with anadditional outer membrane on each side of the area separation wall; and

FIG. 6 is a cross-sectional, side view of the confined space showing theorganic material between the outer membranes in locations where aninterior support structure is not located.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, like reference characters designate likeor corresponding parts throughout the several views. Also in thefollowing description, it is to be understood that such terms as“forward,” “rearward,” “left,” “right,” “upwardly,” “downwardly,” andthe like are words of convenience and are not to be construed aslimiting terms.

As used herein “improved” fire, sound or thermal resistance refers to ameasurable increase in fire resistance, sound resistance or thermalresistance when comparing the present invention with only outermembranes to a conventional area separation walls as described herein.Moreover, “low-conductivity”, “thermally resistive”, “acousticallytransmission resistant”, “electrically non-conductive”, and the like arerelative to conventional area separation walls which are composed ofmore than outer membranes.

Referring now to the drawings in general and FIG. 1 in particular, itwill be understood that the illustrations are for the purpose ofdescribing a preferred embodiment of the invention and are not intendedto limit the invention thereto. As best seen in FIG. 1, a structurehaving an area separation wall, generally designated 10, is shownconstructed according to the present invention. In the preferredembodiment, the area separation wall is a fire resistance rated, areaseparation wall. More preferably, the fire resistance rated, areaseparation wall is a 2½, 3, 3½ or 4 hour or longer rated firewallaccording to ASTM E119-2003.

The structure having an area separation wall includes a first buildingunit 12 and a second building unit 14. Additional building units 16 mayalso be part of the structure 10. The first building unit 12 and secondbuilding units 14 may be occupiable spaces, which may be residentiallyoccupiable spaces, such as town homes. A town house is generally definedby the 2000 International Residential Code as a single-family dwellingunit constructed as a group of three or more attached units in whicheach unit extends from foundation to roof with open space on at leasttwo sides. An area separation wall 18, constructed according to thepresent invention, is located between each building unit 12, 14, 16.

FIG. 2 is a side view of one embodiment of the area separation wall 18including an interior support structure 22 having at least one outermembrane 24 on each side of the interior support structure 22, and amaterial barrier 26 between the outer membranes 24.

In an embodiment, there are only outer membranes. In other words, theouter membranes are on the outside of the wall studs rather than havinga membrane on each side of both wall studs.

In a preferred embodiment, the material barrier 26 is a substantiallyorganic material barrier.

The interior support structure 22 includes at least two structurallyindependent interior support members 28. The structurally independentinterior support members 28 include a plurality of vertical members suchas conventional 2×4. The 2×4 may be made of wood or metal.Alternatively, the plurality of vertical members may be 2×10 or lessthickness dimension and constructed of wood, metal, or other materials.The plurality of vertical members may be spaced apart less than about 24inches and may include cross bracing 30 at about their mid height. Thearea separation wall 18 includes a physical gap 32 between thestructurally independent interior support members 28. The plurality ofvertical members may be staggered to aid in acoustic transmissionresistance.

Sound travels as a compression wave through air. When sound strikes abarrier such as a wall, vibrations occur. Thus, wall studs can act as aconduit for acoustic transmission. However, by staggering the wallstuds, acoustic transmission resistance is increased.

A tying structure 34 connects the first unit 12 and the second unit 14.The tying structure 34 may be a conventional 2×8. The tying structure isoverlaid top plates 37 that is attached to the top edge of the interiorsupport members 28. A bottom plate 36 is attached to the bottom edge ofthe interior support members 28. Also, the maximum height of the areaseparation wall preferably is 10 feet, whereupon another wall wouldbegin.

In other embodiments, other tying structures may be used. For instance,other tying structures may be necessary where the occupiable spaces arestaggered either horizontally or vertically. Also, other membraneconfigurations may exist where, for example, part of the fire rated areaseparation wall is exposed as an exterior wall on one side, and notexposed, or as an interior wall, on the other side. Such a configurationmay occur when two adjoining town homes or other structures connected toeither side of a fire rated area separation wall are staggeredvertically or horizontally, thus exposing part of the wall to theexterior environment on one side with no exterior exposure on the otherside. This would likely result in the membranes on the exterior sideconsisting of exterior cladding, building paper and other materials notnormally associated with fire wall construction and performance.

The outer membranes 24 preferably are a fire resistant wallboard,including Type X or Type C gypsum wallboard (GWB) as defined in ASTMC11. The gypsum wallboard preferably conforms to ASTM Test C-36-96.However, other types of wallboard may be used. A single outer membranemay be placed on either side of the interior support structure. However,as seen in FIG. 5, two or more outer membranes may be placed on eitherside of the interior support structure. As seen in FIG. 4, unequalnumbers of outer membranes may be placed on either side of the interiorsupport structure. For instance, a single outer membrane 24 may beplaced on one side of the interior support structure. In a preferredembodiment, two or more outer membranes 24 may be placed on each side ofthe interior support structure. The use of multiple outer membranes 24on each side of the interior support structure aids in acoustictransmission resistance, fire resistance and thermal resistance.

The outer membranes may be of unequal thicknesses on either side of theinterior support structure. In an embodiment, the outer membrane oneither side of the interior support structure may be of differentmaterials.

The substantially organic material barrier 26 between the outermembranes 24 may be selected from the group consisting of fibrousmaterial, granular material, pellet material, aggregated material,agglomerated material, closed cell foam, open cell foam, fireretardants, binders and mixtures thereof. The substantially organicmaterial barrier 26 may be a natural material. The natural material maybe cellulosic. The substantially organic material barrier 26 may be anacoustically transmission resistant material.

The substantially organic material barrier 26 may also include inorganicmaterials. The inorganic material is selected from the group consistingof fiberglass, rock wool, pearlite, mineral wool, asbestos, cementitiousmaterials, fire retardants, binders, and mixtures thereof.

In the embodiment of FIG. 6, the substantially organic material barriercompletely fills the area between the outer membranes.

FIG. 3 is a side view of the preferred embodiment of the area separationwall 18 that does not include a tying structure 34 connecting the firstunit 12 and the second unit 14. Instead, the area separation wall 18described in FIG. 3 includes a separate top plate 37 attached to anothertop plate 37 that is attached to the top edge of the interior supportmembers 28. In both embodiments, a bottom plate 36 is attached to thebottom edge of the interior support members 28. Also, in bothembodiments, the maximum height of the area separation wall preferablyis 10 feet, whereupon another wall would begin.

As can be seen, the top of the area separation wall can be formed eitherby a top plate 37 overlaid with a tying structure 34 or by a top plate37 overlaid with a second top plate 37 separated by an inch. Thus, thereare two configurations. One is with a single top plate 37 and a tyingstructure 34 that joins the two walls (shown in FIG. 2) and the other istwo separate top plates with a space between them (shown in FIG. 3). Ineither case, this results in a double top plate being formed.

As best seen in FIG. 6, the material barrier 26 may completely fill thearea between the outer membranes 24 as well as the area between theinterior support structure 22 as seen in FIG. 2.

Certain modifications and improvements will occur to those skilled inthe art upon a reading of the foregoing description. It should beunderstood that all such modifications and improvements have beendeleted herein for the sake of conciseness and readability but areproperly within the scope of the following claims.

1. A structure having an area separation wall, said structurecomprising: (a) a first building unit; (b) a second building unit; and(c) an area separation wall having only outer membranes, said outermembranes also providing acoustic attenuation whereby the areaseparation wall provides improved fire, thermal and acoustic resistanceand combinations thereof.
 2. The structure according to claim 1, furtherincluding a tying structure connecting said area separation wall to saidfirst unit and said second unit.
 3. An area separation wall for astructure, said area separation wall comprising: (a) an interior supportstructure; (b) at least one outer membrane on each side of said interiorsupport structure, said outer membranes providing acoustic attenuation;and (c) a substantially organic material barrier between said outermembranes whereby the area separation wall provides improved fire,thermal, and acoustic resistance and combinations thereof.
 4. The areaseparation wall according to claim 3, wherein said interior supportstructure includes at least two structural interior support membersincluding a plurality of spaced apart, vertical members.
 5. The areaseparation wall according to claim 4, wherein said plurality of verticalmembers are spaced apart no more than about 24 inches.
 6. The areaseparation wall according to claim 4, wherein the plurality of verticalmembers are 2×10 or less thickness dimension of a material selected fromthe group consisting of wood, metal, other building materials, andcombinations thereof.
 7. The area separation wall according to claim 4,wherein said plurality of vertical members further include cross bracingat about the mid height of said plurality of vertical members.
 8. Thearea separation wall according to claim 4, further including a physicalgap between said structural, interior support members.
 9. The areaseparation wall according to claim 3, wherein each of said outermembranes are fire resistant wallboard.
 10. The area separation wallaccording to claim 9, wherein said fire resistant wallboard is a gypsumwallboard (GWB) Type X or Type C as defined in ASTM C11 (Committee C11on Gypsum and Related Building Materials and Systems).
 11. The areaseparation wall according to claim 10, wherein said gypsum wallboardconforms to ASTM Test C-36-96.
 12. The area separation wall according toclaim 3, wherein said substantially organic material barrier is selectedfrom the group consisting of cellulosic material, fibrous material,granular material, pellet material, aggregated material, agglomeratedmaterial, closed cell foam, open cell foam, fire retardants, binders andmixtures thereof.
 13. The area separation wall according to claim 3,wherein said substantially organic material barrier is a naturalmaterial.
 14. The area separation wall according to claim 13, whereinsaid natural material is cellulosic.
 15. The area separation wallaccording to claim 3, wherein the substantially organic material barrierincludes an inorganic material.
 16. The area separation wall accordingto claim 15, wherein said inorganic material is selected from the groupconsisting of fiberglass, rock wool, pearlite, mineral wool, asbestos,cementitious materials, fire retardants, binders, and mixtures thereof.17. The area separation wall according to claim 3, wherein saidsubstantially organic material barrier is an acoustically transmissionresistive material.
 18. The area separation wall according to claim 3,wherein there are an unequal number of like outer membranes.
 19. Thearea separation wall according to claim 3, wherein the outer membranesare of unequal thickness or are made of unlike materials.
 20. The areaseparation wall according to claim 3, wherein the outer membranes aremade of unlike materials and are of unequal thickness.
 21. A structurehaving an area separation wall, said structure comprising: (a) a firstbuilding unit; (b) a second building unit; (c) an area separation wall;said area separation wall including: (i) an interior support structure;(ii) at least one outer membrane on each side of said interior supportstructure, said outer membranes providing acoustic attenuation; and(iii) a substantially organic material barrier between said outermembranes; and (d) a tying structure connecting said area separationwall to said first unit and said second unit, whereby the areaseparation wall provides improved fire, sound, or thermal resistance andcombinations thereof.
 22. The structure according to claim 21, whereinsaid tying structure includes a top plate attached to the top edge ofsaid area separation wall and a bottom plate attached to the bottom edgeof said area separation wall.
 23. The structure according to claim 22,wherein said tying structure and said top plate forms a double topplate.
 24. The structure according to claim 22, wherein said top plateand said bottom plate are less than about 10 feet apart.
 25. Thestructure according to claim 21, wherein said building units is anoccupiable space including residential and a town home.